An analog-type hologram in the related art is a method in which an object wave in which light emitted from a laser is projected to the object and reflected to be incident in a hologram storage medium and a reference wave directly incident in the hologram storage medium interfere with each other to generate a fringe pattern and record the generated fringe pattern in the hologram storage medium.
In order to generate hologram by using a hologram information recorded as above, when the reference wave used during hologram recording is incident in the same direction to cause diffraction, the same hologram image as the object is reproduced at a position where the object is originally positioned.
When the hologram generated in an analog mode is generated once, the hologram cannot be changed, and as a result, a new hologram recording process is required whenever the object is changed, and there is a limit in resolution of the hologram image generated in an optical mode and a view volume view volume of an observer. Therefore, a hologram display requires a large capacity of spatial bandwidth in order to provide the size and a viewing angle of an existing display level.
Meanwhile, a calculation equation of a generation principle of the hologram fringe pattern by interference of the object wave for the object and the reference wave is processed through computer modeling when the digital hologram is generated.
In the digital hologram mode, the digital hologram may be regenerated through computer calculation in order to generate a new digital hologram image, and the size and viewing angle of the played hologram image may be improved by visualizing digital hologram data in not an optical hologram display mode but a projection mode.